Sunday, August 31, 2008

Quiet sun, Quiet Ham Band

One of my side hobbies as amateur radio, and as an operator who likes to play around on the 10-meter band, watching the sun is a must.  What is the 10 meter band? And why is the 10 meter band  so dependent on what is going at the sun?  

The 10 meter band of amateur radio runs from about 28 MHz to around 29 MHz in the radio frequency spectrum.  You may be familiar with radios that work close to this frequency range already from your car or RV. Remember CB radio? Yep, these radios operate on the 11 meter band, or from about 26 MHz to 27 MHz, and can be affected by sunspots as well.  The FCC limits the amount of power these CB radios operate to 4 Watts, so generally it is more difficult to contact far away stations.  But it is possible!

With ham radio you can use a lot more power, usually around 200 watts, and up to 1500 watts.  But when solar activity is high, all you really need is a simple antenna and a 25 watt radio and you can easily make contacts around the world.  During the last peak solar cycle I would routinely contact stations in Europe on my drive into work from my car, and then chat with operators in Japan, Australia, and China on the way home.

The 10 meter band can be a fun and challenging band to operate on because it is so heavily dependent on the sun's sunspot level. When the sun is churning out lots of electromagnetic energy the F layer in the earth's ionosphere will act as a mirror, bouncing transmissions back towards the earth.  Since this layer is so high in our atmosphere, a single hop will travel up to 3000 miles.  


Right now we are at what is known as solar minimum and the radio has been pretty quiet. Some scientists are a little puzzled that things have been quiet for this long.  It looks like activity on 10 meters should really start to pick up over the couple of years as the 11 year solar cycle progresses!

No comments: